Telemicroscopic instruments are widely used for magnifying a work area during precision work such as delicate surgery, dental work, inspection of circuit board solder joints, assembly of miniature parts, and jewelry making. A typical telemicroscopic instrument includes a pair of telemicroscopic loupes which are adjustably mounted to an eyeglass frame or head mount. The telemicroscopic loupes combine the long working distance of the telescope with the high quality magnification of the microscope. This type of optical instrument provides the user with a magnified image of the work area with a field of view at about arms length. Hence, the wearer is able to coordinate the work being performed by the hands with what is being seen by the eyes. A Galilean type of telemicroscope is disclosed in copending patent application Ser. No. 08/093,839, filed Jul. 19, 1993 and assigned to the assignee of the present invention, the disclosure of which is hereby incorporated by reference.
As mentioned, the telemicroscope is typically mounted on either an eyeglass frame or special head mount. U.S. patent application Ser. No. 08/093,831, filed Jul. 19, 1993 and assigned to the assignee of the present invention, the disclosure of which is hereby incorporated by reference, discloses an ocular mounting assembly for mounting a telemicroscope upon a pair of conventional spectacle frames and permitting adjustment or positioning in five different ways. As can be seen in FIG. 2 of the referenced application, the spectacles to which the telemicroscope is mounted by means of the ocular mounting assembly is essentially conventional in construction. The ocular mounting assembly is mounted to the spectacle frame below the bridge piece thereof, and the eye glasses are positioned on the user's face in the usual manner.
Mounting the telemicroscope so that it depends from the bridge of the spectacle frame has certain disadvantages due to the positional relationship between the lenses of the telemicroscope, the lenses of the eye glasses, and the wearer's own eyes. In particular, the telemicroscope positioned thus is relatively far away from both the lenses of the spectacle's and the wearer's eyes, thus undesirably reducing the field of vision. Moreover, in a conventional pair of spectacle frames, the lens encircling rims of the frames and the lenses mounted therein are disposed almost perpendicularly to the temple pieces of the frames. This causes aberrations introduced by the lower portion of the eye glass lenses since the lenses of the telemicroscope are often disposed at an angle with respect to the lenses of the spectacles; thus, an optical axis defined between the wearer's eye and the microscope lenses will cross the plane of the eye glass lens at an undesirable, oblique angle.
Furthermore, the weight of a telemicroscope, camera or similar device can be considerable. In a conventional eyeglass frame, the weight is supported mainly on very small nose pads which are mounted on the face side of the frames. The pressure exerted on these packs frequently leads to chafing and soreness.
Clearly, there is a need for a redesigned spectacle frame which is relatively conventional in appearance, but permits the user of a telemicroscope or similar instrument to use such an instrument with optimum viewing results. In particular, there is a need for a redesigned spectacle frame which mounts the telemicroscope closer to the lenses of the spectacles and the wearer's own eyes. There is also a need for a redesigned frame which allows the telemicroscope to be disposed with an optical axis defined between the wearer's eye and the lenses of the telemicroscope to be more or less perpendicular to the lenses of the eye glasses so as to minimize aberrations in the user's down vision. There is a further need for a frame with improved weight distribution to minimize fatigue, chafing and soreness.